Overhead Communicating Device

ABSTRACT

A power line monitoring device is mounted to a power line. The device includes circuitry for monitoring the power line and communicating information regarding the power line. A ground reference point of the circuitry is electrically coupled to the power line. Therefore, the monitoring device, including its circuitry, has substantially the same voltage potential as the power line. Accordingly, there is a substantially equalized or uniform electric field around the device. The substantially equal voltage potential and electric field allow communications with the monitoring device to have reduced noise and interference, as compared to other devices that have different voltage potentials than their corresponding power lines. A pad of semi-conductive material may be disposed between the power line and the electrical conductors to slow a rate of change of the voltage potential of the device circuitry when mounting the device to the power line, thereby minimizing risk of corona discharge.

RELATED PATENT APPLICATIONS

This non-provisional patent application is a continuation-in-part ofU.S. patent application Ser. No. 11/982,588, entitled “CommunicatingFaulted Circuit Indicator Apparatus and Method of use Thereof,” filedNov. 2, 2007, and is related to U.S. patent application Ser. No.[______], entitled “Power Line Energy Harvesting Power Supply,” filed on______ (Attorney Docket No. 13682.117356; EAS-028674). This applicationalso claims priority under 35U.S.C. §119 to U.S. Provisional PatentApplication No. 61/103,603, entitled “Power Line Energy Harvesting PowerSupply,” filed Oct. 8, 2008. The complete disclosure of each of theforegoing priority and related applications is hereby fully incorporatedherein by reference.

TECHNICAL FIELD

The invention relates generally to overhead communicating devices and,more particularly, to power line monitoring devices with built-incommunication mechanisms that are at line potential.

BACKGROUND

Electrical power distribution systems include many independent devicesthat control the distribution of power from power generating facilitiesto meter access points at residential, commercial, and other buildings.Typically, a “transmission system” transports power from a powergeneration facility to a substation, and a “distribution system”distributes the generated power from the substation to an end point. Thetransmission and distribution systems can each include one or moredevices that monitor and/or control power flow. For simplicity, any suchdevice is referred to herein as a “monitoring device.” For example, amonitoring device can include a faulted circuit indicator (“FCI”), acurrent sensor, and/or a voltage sensor.

It is often desirable for monitoring devices to communicate with oneanother or for individual monitoring devices to communicate informationand/or control functions to a remote location. For example, it may bedesirable to communicate information regarding a detected fault in apower line to a remote repair facility. Traditionally, monitoringdevices have communicated using short-range radios disposed in a controlbox, which is hard-wired to the monitoring devices. A user must drive upto the control box to obtain information from the monitoring devices.This solution is point-to-point and would be prohibitively expensive andinefficient if implemented over a wide area with many sensor nodes.

Therefore, a need exists in the art for an improved means forcommunicating information from a power line monitoring device.

SUMMARY

A monitoring device described herein can easily be secured to a powerline without de-energizing or otherwise compromising the integrity ofthe power line. The monitoring device includes a current transformer(“CT”) that captures energy via magnetic flux from the power line towhich it is secured. Circuitry associated with the CT converts theenergy captured by the CT into energy that may be used by one or moreother electrical devices. For example, the energy may power a sensor,monitor, radio, and/or other device associated with the CT and/or theconductor.

The sensor monitors and collects information related to the power line.For example, the sensor can collect information regarding a current onthe power line, a voltage on the power line, a temperature on the powerline, and/or information regarding whether a vibration is present on thepower line. A radio or other communications device communicates at leasta portion of the collected information to a remote location. Forexample, the information can be communicated to a central utilitycompany associated with the power line and/or monitoring device.

A ground reference point of the device circuitry is electrically coupledto the power line via one or more electrical conductors. Therefore, themonitoring device, including its circuitry, has substantially the samevoltage potential as the power line. Accordingly, there is asubstantially equalized or uniform electric field around the device. Thesubstantially equal voltage potential and electric field allowcommunications with the monitoring device to have reduced noise andinterference, as compared to another communication device that has adifferent voltage potential than the power line to which it is attached.

A voltage potential of the monitoring device may be substantially lowerthan the voltage potential of the power line prior to electricallycoupling the ground reference point of the device circuitry to the powerline. A pad of semi-conductive material may be disposed between thepower line and the electrical conductors to slow a rate of change of thevoltage potential of the device circuitry when mounting the device tothe power line. Slowing down this rate of change can minimize risk ofcorona discharge upon electrically coupling the ground reference pointto the power line.

In one exemplary embodiment, a power line monitoring device includes asensor that collects information regarding a power line to which thepower line monitoring device is mounted. The power line monitoringdevice includes a communications device that communicates at least aportion of the information collected by the sensor to a location remotefrom the power line monitoring device. The communications devicecomprises electrical circuitry, which includes a ground reference point.The power line monitoring device includes means for electricallycoupling the ground reference point of the communications device to thepower line such that the ground reference point and the power line havesubstantially equal voltage potentials.

In another exemplary embodiment, a power line monitoring device includesa sensor that collects information regarding a power line to which thepower line monitoring device is mounted. The power line monitoringdevice includes a communications device that communicates at least aportion of the information collected by the sensor to a location remotefrom the power line monitoring device. The power line monitoring devicealso includes a circuit board that comprises circuitry associated withthe sensor and the communications device. The circuitry includes aground reference point that is electrically coupled to the power linewhen the power line monitoring device is mounted to the power line. Avoltage potential of the ground reference point is raised based on avoltage potential of the power line when the power line monitoringdevice is mounted to the power line. The power line monitoring deviceincludes means for slowing a rate of voltage potential change of theground reference point when the power line monitoring device is mountedto the power line.

In another exemplary embodiment, a power line monitoring device includesa sensor that collects information regarding a power line to which thepower line monitoring device is mounted. The power line monitoringdevice includes a communications device that communicates at least aportion of the information collected by the sensor to a location remotefrom the power line monitoring device. A circuit board of the power linemonitoring device comprises circuitry associated with the sensor and thecommunications device. The circuitry includes a ground reference point.A housing at least partially encloses the circuit board. A firstelectrically conductive member is coupled to the housing. The firstelectrically conductive member is disposed outside of the housing andelectrically contacts the power line when the power line monitoringdevice is mounted to the power line. At least a second electricallyconductive member of the power line monitoring device extends throughthe housing and electrically couples the first electrically conductivemember to the ground reference point of the circuitry, thereby raising avoltage potential of the ground reference point in accordance with avoltage potential on the power line when the power line monitoringdevice is mounted to the power line.

These and other aspects, objects, features, and embodiments will becomeapparent to a person of ordinary skill in the art upon consideration ofthe following detailed description of illustrative embodimentsexemplifying the best mode for carrying out the invention as presentlyperceived.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the invention and the advantagesthereof, reference is now made to the following description, inconjunction with the accompanying figures briefly described as follows.

FIG. 1 is a block diagram depicting a power line monitoring device, inaccordance with certain exemplary embodiments.

FIG. 2 is a flow chart illustrating a method for communicating faultedcircuit indicator information using the power line monitoring device ofFIG. 1, in accordance with certain exemplary embodiments.

FIG. 3 is flow chart illustrating a method for transmitting informationfrom the power line monitoring device of FIG. 1 to a remote location, inaccordance with certain exemplary embodiments.

FIG. 4 is a flow chart illustrating a method for clearing fault eventsand line state history, in accordance with certain exemplaryembodiments.

FIG. 5 is a flow chart illustrating a method for communicating data fromthe power line monitoring device of FIG. 1 to individuals and/or anoutage management system, in accordance with certain exemplaryembodiments.

FIG. 6 is a side elevation view of a power line monitoring device, inaccordance with certain exemplary embodiments.

FIG. 7 is a top elevation view of the monitoring device of FIG. 6, inaccordance with certain exemplary embodiments.

FIG. 8 is perspective side view of the monitoring device of FIG. 6, inaccordance with certain exemplary embodiments.

FIG. 9 is a rear elevation view of the monitoring device of FIG. 6, inaccordance with certain exemplary embodiments.

FIG. 10 is a front elevation view of the monitoring device of FIG. 6, inaccordance with certain exemplary embodiments.

FIG. 11, which comprises FIGS. 11A and 11B, is a circuit diagram for acircuit of the monitoring device of FIG. 6, in accordance with certainexemplary embodiments.

FIG. 12 is a front view of two split core sections of a currenttransformer (“CT”) of the monitoring device of FIG. 6, in accordancewith certain exemplary embodiments.

FIG. 13 is a side view of one of the split core sections illustrated inFIG. 12, in accordance with certain exemplary embodiments.

FIG. 14 is a front view of two split core sections of the monitoringdevice of FIG. 6, in accordance with certain exemplary embodiments.

FIG. 15 is a side view of one of the split core sections illustrated inFIG. 14, in accordance with certain exemplary embodiments.

FIG. 16 depicts a method for forming a winding on a CT split coresection, in accordance with certain exemplary embodiments.

FIG. 17 is a front view of a first CT arm of the monitoring device ofFIG. 6, in accordance with certain exemplary embodiments.

FIG. 18 is a side cross-sectional view of the CT arm illustrated in FIG.17, in accordance with certain exemplary embodiments.

FIG. 19 is a front view of a second CT arm of the monitoring device ofFIG. 6, in accordance with certain exemplary embodiments.

FIG. 20 is a side cross-sectional view of the CT arm illustrated in FIG.19, in accordance with certain exemplary embodiments.

FIG. 21 is a front elevation view of a monitoring device housing of themonitoring device of FIG. 6, in accordance with certain exemplaryembodiments.

FIG. 22 is a side elevation view of the monitoring device housingillustrated in FIG. 21, in accordance with certain exemplaryembodiments.

FIG. 23 is a perspective side view of the monitoring device housingillustrated in FIG. 21, in accordance with certain exemplaryembodiments.

FIG. 24 is a side cross-sectional view of a portion of the monitoringdevice housing illustrated in FIG. 21, in accordance with certainexemplary embodiments.

FIG. 25 is a cross-section of a female connector, in accordance withcertain exemplary embodiments.

FIG. 26 is a cross-section of a male connector, in accordance withcertain exemplary embodiments.

FIG. 27 is a front elevation view of a clamp arm of the monitoringdevice of FIG. 6, in accordance with certain exemplary embodiments.

FIG. 28 is a front perspective view of the clamp arm illustrated in FIG.27, in accordance with certain exemplary embodiments.

FIG. 29 is a rear elevation view of the clamp arm illustrated in FIG.27, in accordance with certain exemplary embodiments.

FIG. 30 is a rear perspective view of the clamp arm illustrated in FIG.27, in accordance with certain exemplary embodiments

FIG. 31 is a front elevation view of a clamp pad of the clamp arm ofFIG. 27, in accordance with certain exemplary embodiments.

FIG. 32 is a cross-sectional view of another clamp pad of the clamp armillustrated in FIG. 27, in accordance with certain exemplaryembodiments.

FIG. 33 is a side elevation view of a clamp spring of the monitoringdevice of FIG. 6, in accordance with certain exemplary embodiments.

FIG. 34 is a side, partially cross-sectional view of a power linemonitoring device, in accordance with certain alternative exemplaryembodiments.

FIG. 35 is a side elevation view of the monitoring device of FIG. 34, inaccordance with certain exemplary embodiments.

FIG. 36 is a top elevation view of the monitoring device of FIG. 34, inaccordance with certain exemplary embodiments.

FIG. 37 is an exploded perspective side view of the monitoring device ofFIG. 34, along with a semi-conductive interface pad, in accordance withcertain exemplary embodiments.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

An improved means for monitoring power on a power line is describedherein. In particular, the exemplary embodiments provide a power linemonitoring device, which is configured to be disposed on a power line.The monitoring device includes circuitry for monitoring power flow onthe power line and communicating information regarding the power flowand/or power line with at least one other device. A ground referencepoint of the circuitry is electrically coupled to the power line.Therefore, the monitoring device, including the circuitry therein, hassubstantially the same voltage as the power line. Accordingly, there isa substantially equalized or uniform electric field around the device.The substantially equal voltage potential and electric field allowcommunications with the monitoring device to have reduced noise andinterference, as compared to communicating power line monitoring devicesthat have different voltage potentials than the power line to which theyare mounted.

Turning now to the drawings, in which like numerals indicate likeelements throughout the figures, exemplary embodiments are described indetail. FIG. 1 is a block diagram depicting a power line monitoringdevice 100, in accordance with certain exemplary embodiments. Themonitoring device 100 is electrically connected to a power line 116. Theterm “power line” is used herein to refer to any type of electricalconductor that transmits electricity from one location to another. Forexample, the power line 116 can include one or more utility cables,whether above ground, underground, or otherwise.

Generally, the connection between the monitoring device 100 and thepower line 116 is provided by a clamping mechanism that ensures a strongconnection between the monitoring device 100 and the power line 116. Themonitoring device 100 can be powered in a variety of ways. In certainexemplary embodiments, the monitoring device 100 can be powered by amagnetic field generated by the power line 116 to which the monitoringdevice 100 is connected, along with a battery that can power themonitoring device 100 should current in the attached power line 116 beinterrupted. Alternative power supplies include, but are not limited to,solar power, vibration, radio frequency energy, thermal energy, currentpassing through the power line 116, a rechargeable battery orsupercapacitor that harvests energy from the current in the power lineby using a current transformer, or by utilizing the reference voltagefrom an energized conductor to an adjacent ground.

The monitoring device 100 comprises a sensor 102 that measuresconditions on the power line 116. In certain exemplary embodiments, thesensor 102 can measure in real time or near-real time the current andvoltage on the power line 116. In certain alternative exemplaryembodiments, other types of sensors 102 can be used that are capable ofmeasuring any suitable parameter for conditions that can be present onthe power line 116 or the monitoring device 100 itself, including butnot limited to, line temperature, line tilt, ambient temperature, windspeed, liquid levels of electrical components, dissolved gas content orpressure from a monitored transformer, battery status, frequency,harmonics, zero crossings, vibration, and/or power factor. The sensor102 can be configured to measure one or more conditions. In certainexemplary embodiments, two or more sensors 102 can be combined tomeasure multiple conditions. The sensor 102 communicates themeasurements to a controller 104. The twin “sensor data” is used hereinto refer to any information provided from the sensor 102, including anymeasurements provided from the sensor 102 to the controller 104. Incertain exemplary embodiments, the monitoring device 100 can beelectrically connected to a neutral line (not shown) and the sensor 102can comprise a current sensor for finding current imbalances.

The controller 104 analyzes the sensor data it receives and takesappropriate actions in response to the data. In certain exemplaryembodiments, the controller 104 includes a microcontroller programmed toanalyze the sensor data and to respond appropriately. In certainalternative exemplary embodiments, the controller 104 includes anysuitable control mechanism capable of receiving sensor data andcontrolling peripheral systems, such as a memory 108, a communicationsfacility 110, and an indicator 106. For example, the controller 104 cancomprise any combination of analog and/or digital electronics capable ofestablishing that a fault event has occurred.

In certain exemplary embodiments, the controller 104 can be programmedto recognize certain changes in the sensor data as fault events. Forexample, the controller 104 can treat a drop in current in excess of aprogrammed threshold as indicative of the existence of a fault. However,the controller 104 can be programmed to identify any condition thatoccurs on the power line 116 as indicative of a fault. For example, thecontroller 104 can be programmed to identify a surge in current orvoltage in excess of a predetermined threshold, a temperature reading inexcess of a predetermined threshold, and/or vibration in excess of apredetermined threshold as a fault. The thresholds can be defined by autility company employing the monitoring device 100 in an electricaltransmission or distribution system and can vary based on conditions ina particular area. If the controller 104 determines that a fault hasoccurred, it can communicate that fact to an indicator 106, a memory108, and/or a communications facility 110 of the monitoring device 100.In certain alternative exemplary embodiments, the sensor 102 cancomprise circuitry for determining whether a fault condition hasoccurred and for notifying the controller 104 of the fault event.

In embodiments where the controller 104 receives sensor data from thesensor 102, the controller 104 can be further programmed to identifycertain other data that can be valuable to a utility company indiagnosing problems or inefficiencies in a transmission or distributionsystem. The controller 104 can be configured to record data in thememory 108 for later analysis by the utility company, a line technician,or another interested party. By way of example, an increase intemperature on a power line 116 may not result in a fault event, but mayindicate that the power line 116, or some of its nearby equipment suchas transformers, capacitors, capacitor banks, circuit breakers, andfuses, has developed a flaw that is creating additional resistance onthe power line 116 and reducing efficiency. Similarly, the controller104 can be programmed to monitor the zero crossings that occur on thepower line 116 over a certain period of time. Information relating tozero crossings can be used to identify harmonics and momentaries thatpotentially indicate an unstable condition. Because the controller 104(and/or sensor 102) has identified the condition before a fault hasoccurred, the utility company can determine whether remedial action isnecessary to improve the performance of the transmission system or toprevent a fault that may result in a loss of power to the utilitycompany's customers.

The controller 104 can be further programmed to identify data relatingto the monitoring device 100 itself and to record that data in thememory 108. For example, the controller 104 can identify and recordbattery status, geographic coordinates, ambient temperature, wind speed,liquid levels, dissolved gas content, pressure, and/or any othersuitable data that may be of interest to a utility company.

The controller 104 can be further configured to communicate faultdeterminations to an indicator 106 and to communicate faultdeterminations and sensor data to a communications facility 110. If, asdescribed above, the controller 104 (and/or sensor 102) determines thata fault event has occurred, then the controller 104 can communicate thatinformation to an indicator 106. Further, without regard to whether afault event has been established, the controller 104 can communicatesensor data to the memory 108 or to a communications facility 110.

For example, the controller 104 can be programmed to transmit sensordata from the sensor 102 after the passage of a set period of time—forexample, once per day—without regard to the data's contents. Suchprogramming would allow a utility company to have frequent updatesregarding the performance of the transmission or distribution system.The controller 104 also can be programmed to store sensor data after thepassage of a set period of time—for example, once per hour—and then totransmit the stored information over a different period of time—forexample, once per day. The controller 104 can also be programmed tosynchronize to other sensors deployed along the power line 116 ordistribution system in order to provide an accurate snapshot of theentire power line 116 or distribution system at synchronized timesthroughout the day. The periodicity of recording and transmitting ofsensor data is at the discretion of the utility company to meet theparticular needs of the environment in which the monitoring device 100is deployed. The controller 104 also can be programmed to transmit anysensor data that meets any of the fault or storage conditions describedabove.

The indicator 106 can be a display that is mounted on the monitoringdevice 100 and situated such that it can be viewed from a distance.Thus, the indicator 106 can provide a visible indication that a faulthas occurred. In certain exemplary embodiments, the indicator cancomprise a high visibility display device. However, the indicatoralternatively can be a liquid crystal display (LCD) or other similardisplay device. Additionally, the indicator 106 can emit an audiblesound that can alert a technician in the general vicinity of themonitoring device 100 that the monitoring device 100 has detected afault condition. The audible indicator 106 can be in addition to, or analternative to, a visible indicator 106.

The memory 108 can be any suitable storage device, such as flash memoryor dynamic random access memory (DRAM). If the controller 104 determinesthat sensor data should be recorded, such as when the data represents anunusual condition or a fault, the controller 104 can record that data inthe memory 108, and can optionally record information that relates tothe data, such as the time the data was measured, the geographiccoordinates of the FCI that recorded the data, the ambient conditions atthe time the data was recorded, or any other data that the FCI hasmeasured or recorded.

The memory 108 also can store information that relates to the monitoringdevice 100. For example, in certain exemplary embodiments, uponinstallation, the memory 108 can be programmed with the globalcoordinates of the monitoring device 100. Alternatively, the memory 108can store other identifying information, such as, but not limited to,the street address of the installation, a unique identifier for themonitoring device 100, grid coordinates, or an identifier for a nearbyutility pole or other landmark.

The communications facility 110 provides a system that is capable oftransmitting data to a remote location 114. In certain exemplaryembodiments, the communications facility 110 communicates with theremote location 114 using cellular technologies, such as GSM (GlobalSystem for Mobile communications) or CDMA (Code Division MultipleAccess). The communications facility 110 also can include components forany number of wireless or wired communications protocols, including, butnot limited to, any of the 802.11 standards, Bluetooth (IEEE 802.15.1),ZigBee (IEEE 802.15.4), Internet Protocol, licensed or un-licensedradio, fiber, or power line carrier communications technologies. Thecommunications facility 110 can provide the function of communicatingsensor data to a remote location 114.

In certain exemplary embodiments, the remote location 114 can be relatedto a utility company's central office and has the capability ofsimultaneously monitoring communication feeds from numerous monitoringdevices 100 and communicating information from those feeds to an entityor individual that is responsible for repair and maintenance to thetransmission or distribution system. In this embodiment, the remotelocation 114 comprises a central server that is connected to a utilitycompany's outage management system. Upon receiving communication offault or sensor data, the server then processes the information andtranslates the data format as necessary into an appropriate format suchas, but not limited to, Distributed Network Protocol (DNP),Inter-Control Center Communications Protocol (ICCP), Multispeak, orother communications protocols. The server then transmits theinformation to the outage management system, where it can be viewed onthe utility company consoles. Either the server or the outage managementsystem also can provide direct communications to individuals who canaddress the problem. For example, upon receiving information relating toa fault, the system can automatically direct an electronic mail messageor telephone call to a line technician in the area, who can receive themessage on a mobile communications device, such as a wireless phone,personal digital assistant, or other suitable communications device.

In certain alternative exemplary embodiments, the remote location 114can comprise a system capable of generating information that isaccessible by the utility company, such as a World Wide Web page thatgraphically displays information to the viewer. In this embodiment, uponreceiving a communication of fault or sensor data, the server generatesa web page that, if accessed, displays some or all of that informationto the viewer. Utility company representatives can then visit the webpage to retrieve the data. The server in this embodiment also canprovide communications to individuals via telephone or electronic mailmessage, as described with respect to the previous exemplary embodiment.

In another alternative embodiment, the remote location 114 can be acommunications device, such as a cellular telephone or a personaldigital assistant (PDA). The remote location also can be any locationaccessible via the Internet, such as an electronic mail address. In thisembodiment, the communications facility 110 uses cellular communicationsto communicate directly with the remote location 114 via telephone,short message service (SMS) message, or electronic mail. In thisembodiment, the monitoring device 100 can provide direct notice toindividuals who are in a position to address any concerns that raised bythe communication.

The communications facility 110 also can facilitate communicationsbetween two or more monitoring devices 100. This embodiment isespecially advantageous when multiple monitoring devices 100 are locatedwithin a short distance of one another. By way of example only, it maybe desirable to install three monitoring devices 100 on a singlethree-phase power line, such that one monitoring device 100 monitorseach individual phase. In such an implementation, it can be desirable toimplement cellular communications in the communications facility 110 ofone of the monitoring devices 100. The monitoring devices 100 thencommunicate with one another using a short range wireless protocol, suchas Bluetooth, WiFi, or ZigBee, or a wired protocol, such as power linecarrier networking. If one of the monitoring devices 100 in whichcellular communications is not installed detects a fault condition, ordetermines that sensor data should be transmitted to a remote locationusing cellular communications, that monitoring device 100 can transmitto the cellular-enabled monitoring device 100 using the short rangewireless protocol or the wired protocol, and the cellular-enabledmonitoring devices 100 can relay the transmission to the remote location114. This multiple monitoring device 100 embodiment is also applicableto monitoring devices 100 located in close proximity to each other ondifferent power lines or other equipment. “Close proximity” can bewithin the communications distance of the short range wireless protocolor the wired protocol.

In exemplary embodiments, a reset interface 112 can have two distinctreset instructions for the monitoring device 100: an indicator reset anda memory reset. The indicator reset instruction removes a faultindication, while the memory reset instruction clears at least some ofthe sensor data from the memory 108. The memory reset instruction cancomprise parameters that indicate the portions of the memory to becleared. For example, the memory reset instruction can specify that onlysensor data recorded before a certain date should be cleared, that allsensor data should be cleared, that sensor data and information relatingto the monitoring device 100 should be cleared, that all data other thaninformation relating to the monitoring device 100 should be cleared,and/or other suitable parameters that identify which memory should beerased. While both the indicator reset and the memory reset instructionscan be triggered by the same event, it may be desired in some instancesto reset one or the other in isolation.

For example, in certain exemplary embodiments, the controller 104 can beprogrammed to respond to the resumption of proper current flow after afault event by issuing an indicator reset instruction but not a memoryreset instruction. In this mode of operation, a record of the faultevent, as well as the conditions that accompanied the event, will remainin memory 108 even though the fault indicator 106 has been cleared. Theinformation can then be downloaded from the memory 108 and analyzed, andthe monitoring device 100 will not indicate a fault situation when nonepresently exists. Thus, the invention can provide automatic reset whenproper current flow resumes, while also storing data that can be used todiagnose and locate transient or intermittent faults.

Additionally, the reset interface 112 can receive reset instructionsdirectly from a technician that is “on-site.” In certain exemplaryembodiments, the technician provides reset instructions by activatingone or more buttons (not shown) on the monitoring device 100 or akeyboard (not shown) connected to the monitoring device 100. In certainalternative exemplary embodiments, reset instructions can be providedvia switches or other common input techniques such as from a computer,PDA, or a cellular telephone.

In certain exemplary embodiments, the sensor 102, controller 104, memory108, communications facility 110, and reset interface 112 can beprovided inside a weatherproof housing, while the indicator 106 isdisposed on the outer surface of the housing such that the indicator 106can be viewed from a distance. In certain alternative exemplaryembodiments, each component can be disposed either inside or outside thehousing. The housing can be clamped to the power line 116 with aclamping mechanism, and the sensor 102 can be logically coupled to aportion of the clamping mechanism.

FIG. 2 is a flow chart illustrating a method 200 for communicatingfaulted circuit indicator information using the monitoring device 100 ofFIG. 1, in accordance with certain exemplary embodiments. The method 200will be described with reference to FIGS. 1 and 2.

In step 205, the sensor 102 collects data from the power line 116, themonitoring device 100, or its surroundings. In step 210, the controller104 analyzes the collected data to determine whether the collected dataconstitutes a fault, whether the data should be reported, and/or whetherthe data should be stored in memory 108.

In step 215, the controller 104 determines whether a fault condition hasoccurred based on the analysis conducted in step 210. If the controller104 determines in step 215 that a fault condition has occurred, then themethod 200 branches to step 220. In step 220, the controller 104communicates the presence of the fault condition to the indicator 106,which displays an indication that a fault has occurred. The method 200then proceeds to step 225.

Referring back to step 215, if the controller 104 determines that afault condition did not occur, then the method 200 branches directly tostep 225.

In step 225, the controller 104 determines whether the collected dataand/or the fault condition is such that reporting is required. Incertain exemplary embodiments, the controller 104 can be programmed tomake this determination based on the data itself, or based on otherfactors, such as the passage of a set period of time, or a direct demandfrom the utility company. If reporting is required, then the method 200branches to step 230, wherein the controller 104 communicates the sensordata and/or the fault information, together with a communicationinstruction, to the communications facility 110, which transmits thecollected data and/or the fault information to the remote location 114.Step 230 will be described in further detail hereinafter with referenceto FIG. 3. The method 200 then proceeds to step 235.

Referring back to step 225, if the controller 104 determines that thedata should not be reported, the method 200 branches directly to step235.

In step 235, the controller 104 determines whether the collected dataand/or fault information should be stored in the memory 108. Thedetermination can be made based on the controller's programming, asdescribed above with respect to FIG. 1. If yes, then the method 200branches to step 240, wherein the controller 104 stores the collecteddata and/or fault information in the memory 108. The method 200 thenproceeds to step 245.

Referring back to step 235, if the controller 104 determines thatstorage is not required, then the method 200 branches directly to step245.

In step 245, the controller 104 determines whether a reset has beentriggered. If a reset has been triggered, the method 200 branches tostep 250, wherein the controller 104 can clear the fault indication, thememory 108, or both. The reset procedure of step 250 is discussed infurther detail hereinafter with reference to FIG. 4.

The method 200 then proceeds to step 255. Referring back to step 245, ifthe controller 104 determines that a resent has not been triggered, thenthe method 200 branches directly to step 255.

In step 255, the controller 200 determines whether to continuemonitoring the power line 116. If yes, then the method 200 branches backto step 205. If not, then the method 200 ends.

FIG. 3 is flow chart illustrating a method 230 for transmittinginformation from the power line monitoring device 100 to the remotelocation 114, in accordance with certain exemplary embodiments. Forexample, the method 230 can be used to transmit fault information and/ordata to the remote location 114, as referenced in step 230 of FIG. 2.The exemplary method 230 will be described with reference to FIGS. 1 and3.

In step 305, the controller 104 determines, based on its programming,the data to be transmitted. For example, this data can includeinformation relating to a fault, if a fault event triggered thetransmission. The data also can relate to measurements of the sensor102, or other information relating to the monitoring device 100, such asits global coordinates.

In step 310, if any of the data to be transmitted resides in the memory108, the controller 104 retrieves that data. In step 315, the controller104 transmits the data to the communications facility 110.

In step 320, the controller 104 determines, based on its programming,whether the data should be transmitted to a remote server or othersimilar system. If the controller 104 determines that data should not betransmitted to a remote server, the method 230 branches to step 335. If,however, the controller 104 determines in step 320 that data should betransmitted to a remote server, then the method 230 branches to step325, wherein the communications facility 110 transmits the data to aremote server. In certain exemplary embodiments, the data transmissionis performed with cellular communications, although in otherembodiments, the transmission may be by any of the wireless or wiredtransmission protocols described above with respect to FIG. 1. Themethod 230 then proceeds to step 330.

In step 330, the remote server communicates data to individuals or autility company's outage management service to allow the individual orutility company to respond to the data. The communicating feature ofstep 330 is discussed in further detail hereinafter with respect to FIG.5. The method 230 then proceeds to step 335.

In step 335, the controller 104 determines, based on its programming,whether the data should be transmitted to an individual, such as a linetechnician. If the controller 104 determines that data should not betransmitted to an individual or individual(s), then the method returnsto step 235 of FIG. 2. If, however, the controller 104 determines thatthe data should be transmitted to an individual, then the method 230branches to step 340, wherein the communications facility 110 uses acellular protocol to transmit the data to an individual orindividual(s). For example, the communications facility 110 could placea telephone call to the individual or individual(s). However, in certainexemplary embodiments, the communications facility 110 can send a textmessage or electronic mail message directly to a cellular enabled deviceor device(s), such as a telephone or a personal digital assistant. Themethod 230 then proceeds to step 235 of FIG. 2.

FIG. 4 is a flow chart illustrating a method 250 for clearing faultevents and line state history according to certain exemplaryembodiments, as referenced in step 250 of FIG. 2. The method 250 will bedescribed with reference to FIGS. 1 and 4.

In step 405, the controller 104 determines, based on its programming,whether a reset signal instructs clearing the memory 108. As describedabove, a variety of events can trigger a reset, and a utility companycan desire to have some events reset at least a portion of the memory108, while others reset only the fault indication. If the controller 104determines that the received reset signal does not instruct resettingthe memory 108, then the method 250 proceeds to step 415.

If, however, the controller 104 determines that the received resetsignal does instruct resetting the memory 108, then the method 250branches to step 410, wherein the controller 104 clears at least aportion of the data from the memory 108, based on the instructions inthe reset signal. The method 250 then proceeds to step 415.

In step 415, the controller 104 determines whether the reset signalinstructs clearing the fault indicator 106. If the controller 104determines that the received reset signal does not instruct resettingthe fault indicator 106, then the method 250 branches to step 255 ofFIG. 2.

If, however, the controller 104 determines that the received resetsignal instructs resetting the fault indicator 106, the method 250branches to step 420, wherein the controller 104 clears any indicationthat a fault has occurred from the fault indicator 106. After clearingthe fault indication, the method 250 proceeds to step 255 of FIG. 2.

FIG. 5 is a flow chart illustrating a method 330 for communicating datato individuals and/or an outage management system according to certainexemplary embodiments. FIG. 5 presumes that a fault or other informationof interest has been detected and has been transmitted to a centralserver. The method 5330 will be described with reference to FIGS. 1 and5.

In step 505 it is determined whether the server can contact the utilitycompany's outage management system (OMS). If the server can contact theoutage management system, the method 330 proceeds to step 510, whereinthe server transmits the data to the OMS. The OMS can then display thedata to operators on the utility company's existing systems. If theserver cannot contact the utility company's OMS, the method 330 branchesto step 515. The remote server also has capability to store all incominginformation for historical purposes. This data historian can be used toanalyze and improve the utility system performance.

In step 515, it is determined whether the server can contact individualsdirectly. If the server cannot contact individuals directly, the method330 proceeds to step 520, wherein the server transmits the data to anindividual via telephone call, text message, electronic mail message, orother similar form of communication. If, in step 515, it is determinedthat the server should not contact individuals, the method 330 branchesto step 525.

In step 525, the server can generate an alternative presentation of thetransmitted data for the utility company. In certain exemplaryembodiments, the server generates a web page or other content that issuitable for Internet transmission that the utility company can visitthrough a standard Internet browser or other network communicationsmechanism. The web page will present the data transmitted by themonitoring device 100 in a graphical or textual form. This method alsoallows for the information to be presented via telephone calls, textmessages, electronic mail, and other similar forms of communication.Once the alternative presentation is generated, the method 330 proceedsto step 530.

In step 530, the location of the transmitting monitoring devices 100 isdetermined. In certain exemplary embodiments, this information isdetermined from the data itself, which preferably contains geographiccoordinates for the monitoring device 100 or the address where themonitoring device 100 is installed. Alternatively, the location of themonitoring device 100 can be determined by resolving a unique identifierfor the monitoring device 100 that is transmitted with the data using atable or other database that includes associations between monitoringdevices 100 unique identifiers and locations. After determining thelocation of the transmitting monitoring devices 100, the method 330proceeds to step 535, wherein a line technician makes any necessaryrepairs.

FIGS. 6-10 illustrate a power line monitoring device 600, in accordancewith certain exemplary embodiments. With reference to FIGS. 6-10, themonitoring device 600 includes a current transformer 610 (“CT”) coupledto a housing 620. The CT 610 is configured to measure alternatingcurrent flowing through an electrical conductor 660 (FIG. 8). Forexample, the electrical conductor 660 can include a power or neutralline or other electrically conductive member to which the monitoringdevice 600 is coupled. As described below, the CT 610 is configured toharvest energy captured from a magnetic field generated by the currentflowing through the conductor 660.

As best seen in FIGS. 14-16, which are described below, the CT 610includes a winding 905 wrapped around a portion of a magnetic core 805.Current flowing through the conductor 660 generates a magnetic fieldthat extends around the conductor 660 and through the winding 905. Thisgenerated magnetic field induces a secondary current onto the winding905 that is directly proportional to the current flowing through theelectrical conductor 660 divided by a number of turns in the winding905.

As would be recognized by a person of ordinary skill in the art havingthe benefit of the present disclosure, a CT typically includes both aprimary winding and a secondary winding. In the exemplary embodimentdepicted in FIGS. 6-10, the electrical conductor 660 and winding 905 actas the primary and secondary windings, respectively, of the CT 610,despite the fact that the electrical conductor 660 is a distinctcomponent from the CT 610. Thus, the term “CT” is used herein to referto an electrical device that measures current of, and harvests energyfrom, a conductor, which may be part of the CT or a separate componentfrom the CT.

The monitoring device 600 includes circuitry 700 (FIG. 11) that convertsthe energy captured by the CT 610 into useful energy. The circuitry 700also may include one or more sensors and/or communication devices, eachof which may be similar to the sensor 102 and communications facility110, respectively, described above with reference to FIGS. 1-5.Alternatively, such sensors and/or communication devices may beindependent of the circuitry 700 but associated with, or incorporatedin, the device 600. For example, such devices may be disposed within thehousing 620. In certain exemplary embodiments, the circuitry 700 ismounted on a circuit board 3405 (FIG. 34) disposed within the housing620. The circuitry 700 is described below with reference to FIG. 11.

The useful energy provided by the circuitry 700 can power one or moredevices associated with the CT 610. For example, the device(s) caninclude one or more sensors (e.g., pressure, sound, level, moisture,temperature, etc., such as the sensor 102), cellular modems, satellitetransceivers, indicating devices (e.g., lights), monitors, radios and/orother communication devices (such as the communications facility 110),and other devices that use electrical energy to operate. The device(s)can be located within the housing 620 or outside of the housing 620. Forexample, the device(s) can be located on or adjacent to the circuitboard 3405. In embodiments in which the device(s) include a radiotransmitter or other communications device, the monitoring device 600can include an antenna 650 that enables communication between the deviceand another device located proximate the monitoring device 600 or remotefrom the monitoring device 600. The antenna 650 can be coupled to thehousing 620 via an antenna connector 655 that maintains the physicalintegrity of the housing 620.

As described below, an electrical connector 670 can route the secondarycurrent from the winding 905 to the circuitry 700. For example, thewinding 905 of the CT 610 can be electrically coupled to the circuitry700 via the electrical connector 670. The electrical connector 670typically includes two insulated electrical lead wires 670A and 670B(FIG. 16). In certain exemplary embodiments, the electrical connector670 can be disposed in a rigid structure, such as a conduit, thatprotects the electrical connector 670 from the environment. The CT 610and the housing 620 can be adapted to receive the electrical connector670 without compromising the integrity of the CT 610 or the housing 620.

In certain exemplary embodiments, a clamping mechanism 630 coupled tothe housing 620 secures the monitoring device 600 to the electricalconductor 660. As described in more detail below, the clamping mechanism630 secures the monitoring device 600 to the conductor 660 withoutcompromising the integrity of the conductor 660 or the system in whichthe conductor 660 operates. That is, the clamping mechanism 630 securesthe monitoring device 600 to the conductor 660 without disconnecting orremoving power from the conductor 660. In certain exemplary embodiments,the clamping mechanism 630 operates in a manner substantially similar tothat disclosed in U.S. Pat. No. 5,397,982, entitled “Releasable Sensorfor Conductor Fault Detection Including a Rigid Trigger Arm,” thecomplete disclosure of which is hereby fully incorporated herein byreference.

In certain exemplary embodiments, the housing 620 includes a pulling eye640 that facilitates connection and disconnection of the monitoringdevice 600 from the conductor 660 using a “hotstick” (not shown). Thepulling eye 640 includes a member that receives a grasping hook of thehotstick during connection or disconnection. Although illustrated in thefigures as having a substantially “U” shape, a person of ordinary skillin the art having the benefit of the present disclosure will recognizethat the pulling eye 640 can have any of a number of different shapesand configurations. The pulling eye 640 can be coupled to the housing620 or integral to the housing 620.

The clamping mechanism 630 includes a body portion 635 and two clamparms 632A and 632B. When the clamping mechanism 630 is in a closedposition, the clamp arms 632A and 632B secure the conductor 660 againstthe body portion 635. Each clamp arm 632A and 632B includes a clampspring 631A and 631B, respectively. The clamp springs 631A and 631B arebiased to maintain the clamp arms 632A and 632B in the closed positionuntil forcibly opened.

As best seen in FIG. 8, which illustrates the clamping mechanism 630 inan open position around the conductor 660, the clamping mechanism 630also includes an actuator arm 690 attached to clamp arm 632A. Theactuator arm 690 holds the clamp arms 632A and 632B open while securingthe monitoring device 600 to the conductor 660. When the clamp arms 632Aand 632B are rotated open, away from the body portion 635, a free side690A of the actuator arm 690 is positioned in a receptacle 691 of clamparm 632B. The receptacle 691 holds the actuator arm 690 in place,thereby preventing the clamp arms 632A and 632B from closing. Theactuator arm 690 can be released from the receptacle 691 by applying aforce to the actuator arm 690, in the direction of the body portion 635.

To secure the monitoring device 600 to the conductor 660, the monitoringdevice 600 can be pressed against the conductor 660, with the clamp arms632A and 632B being disposed in the open position, and the actuator arm690 being disposed in the receptacle 691. The force of the conductor 660pressing against the actuator arm 690 releases the actuator arm 690 fromthe receptacle 691. The clamp springs 631A and 631B, in turn, act toclose the clamp arms 632A and 632B around the conductor 660.

As discussed in more detail below with reference to FIGS. 27-32, theclamp arms 632A and 632B include clamp pads 633A and 633B, respectively.The clamp pads 633A and 633B include raised clamp slots 910 (FIG. 28)extending substantially perpendicularly to a longitudinal axis of theconductor 660. The clamp slots 910 help to minimize the motion of theconductor 660 relative to the clamp arms 632A and 632B by increasing asurface tension between the conductor 660 and the clamp aims 632A and632B. In certain exemplary embodiments, the body portion 635 of theclamping mechanism 630 also includes raised slots 695 that help minimizethe motion of the conductor 660.

As best seen in FIG. 7, the CT 610 includes two CT arms 612A and 612Bthat are adjacent to each other when the CT 610 is in the closedposition. The CT arms 612A and 612B include magnetic core sections 805and 815, respectively. The CT core sections 805 and 815 are describedbelow in detail with reference to FIGS. 12-16. As best seen in FIG. 8,the CT arms 612A and 612B encircle the conductor 660 in operation sothat the magnetic field generated by current flowing through theconductor 660 extends through the winding 905, which is disposed on theCT arm 612A. The magnetic field induces a current onto the winding 905that is routed to the circuitry 700.

Each CT arm 612A, 612B includes a substantially elongated member fromwhich an entry projection 613A, 613B, respectively, extends. The entryprojections 613A and 613B are oriented in a manner that facilitatesopening of the CT aims 612A and 612B when the entry projections 613A and613B are acted on by a conductor 660. To secure the CT 610 to theconductor 660, the CT 610 is moved towards the conductor 660 to positionthe conductor 660 in a “V” area 618 defined by the entry projections613A and 613B. When the conductor 660 presses against the entryprojections 613A and 613B, in the V area 618, the entry projections 613Aand 613B move apart from one another, thereby causing the CT aims 612Aand 612B to open. Once the CT arms 612A and 612B are open, the conductor660 can enter a CT cavity 619 disposed between the CT arms 612A and612B. Once the conductor 660 passes inner surfaces of the CT arms 612Aand 612B, the CT arms 612A and 612B close, encircling the conductor 660.

The CT arms 612A and 612B are spring biased to remain in the closedposition when at rest. Specifically, each of the CT arms 612A and 612Bis coupled to one or more springs, such as springs 611A and 611B, thatmaintain the CT arms 612A and 612B in the closed position when at rest.In certain exemplary embodiments, one or both of the springs 611A and611B creates a conductive path between the conductor 660 and thecircuitry in the housing 620 to ensure that the reference voltage forthe circuitry is the same as that for the conductor 660. In suchembodiments, both CT springs 611A and 611B contact the conductor 660when the conductor 660 is positioned in the CT 610. Because theconductor 660 is in contact with the CT springs 611A and 611B, theconductor 660 makes contact with an electrical node in the circuitrywhich aids in the monitoring device 600 functions.

Adjacent to the entry projections 613A and 613B, the inner surface ofeach CT arm 612A, 612B includes an exit surface 614A, 614B. The exitsurfaces 614A and 614B act in a manner similar to that of the entryprojections 613A and 613B when removing the CT 610 from the conductor660. When a force acts on the monitoring device 600 to remove themonitoring device 600 from the conductor 660, the exit surfaces 614A and614B aid in overcoming the spring force on the CT arms 612A and 612B,thereby forcing the CT arms 612A and 612B into the open position. Oncethe CT arms 612A and 612B are in the open position, the CT 610 may beremoved from the conductor 660. When the CT arms 612A and 612B arereleased from the conductor 660, such that the conductor 660 is nolonger disposed between the CT arms 612A and 612B, the CT arms 612A and612B can return to the closed position.

The CT arms 612A and 612B and the CT springs 611A and 611B areconfigured such that, when the CT 610 is in the closed position, an airgap 617A disposed between the end surfaces 612AA and 612BA of the CTarms 612A and 612B, respectively, at the entry point 618, is minimal insize. Similarly, an air gap disposed between end surfaces (not shown) ofthe CT arms 612A and 612B, opposite the entry point 618, may be minimalin size. In certain exemplary embodiments, each air gap may have a widthof less than one thousandth of an inch, where the width of each air gapis measured from the CT arm 612A end surface adjacent one side of theair gap to the CT arm 612B end surface adjacent another side of the airgap. The minimal sizes of the air gaps allow the CT 610 to harvest moremagnetic flux energy from the conductor as larger air gaps reduce theamount of available energy that can be harvested.

The monitoring device 600 may be installed on the electrical conductor660 in any of a variety of different ways. In certain exemplaryembodiments, the monitoring device 600 is installed by opening theclamping mechanism 630, holding the clamp arms 632A and 632B open withthe actuator arm 690, and, when the actuator arm 690 makes contact withan outer surface 660A of a first segment 660B of the conductor 660,closing the clamping mechanism 630 to secure the monitoring device 600to the conductor segment 660B. Once the monitoring device 600 is securedto the conductor segment 660B, the CT 610 may be installed on theconductor 660 by applying a force at the entry point 618 to open the CTarms 612A and 612B and thereby allow a second segment 660C of theconductor 660 to enter the CT cavity 619. As set forth above, once theconductor segment 660C enters the CT cavity 619, the CT arms 612A and612B close, thereby encircling the conductor segment 660C.

Once the conductor segment 660C is disposed within the CT cavity 619 andthe clamping mechanism 630 secures the conductor segment 660B, the CT610 is able to convert energy contained in the magnetic flux generatedby the conductor 660 into electrical power that is usable by otherdevices. Several issues arise when trying to develop usable energy froma CT 610 while at the same time not affecting the ability of the CT 610to measure current.

In certain exemplary embodiments, the circuitry of the CT 610 isconfigured to harvest energy from a lightly loaded distribution powerline and dissipate excess energy from a heavily loaded line. Thecircuitry includes a regulated power supply that takes advantage of anoptimal power point of the CT 610 This optimal power point is based onthe permeability of the core material, the cross sectional area of thecore, the number of wire turns wrapped around the cross sectional areaof the core, the air gap separating the core halves, the impedance ofthe input stage, the resonant frequency of the circuit, and otherfactors such as wire resistance, switching efficiencies, and otherelectrical factors. This optimum power point can be calculated orempirically determined.

The energy captured by the CT 610 may be stored with one or morecapacitors (not shown) or other energy storage mechanisms. In certainexemplary embodiments, a regulator (not shown) keeps the charge on eachcapacitor from exceeding voltage levels that would damage the circuitryof the CT 610. This regulated voltage may be fed into a switchingregulator (not shown) that regulates the voltage to the output voltageof another device (not shown), such as a sensor 102 and/orcommunications facility 110 (as discussed above in connection with FIGS.1-5), that is being powered by the CT 610 and to charge a battery (notshown) or other energy storage device associated with the CT 610 to theregulated voltage. Circuitry may be used to control the switchingregulator to work at the optimum operating voltage determined as setforth above. The energy captured by the CT 610 is available to beprocessed by the other device.

FIG. 11, which includes FIGS. 11A and 11B, depicts a circuit 700utilized by the monitoring device 600 to process the captured energy, inaccordance with certain exemplary embodiments. The circuit 700 isdescribed herein with reference to FIGS. 6-11. As discussed above,magnetic flux energy scavenged by the CT 610 is routed by way of theelectrical connector 670 to a circuit board in the housing 620. Incertain exemplary embodiments, the circuit board can include the circuit700 and any other circuitry associated with the monitoring device 600.

In certain exemplary embodiments, the circuit 700 includes means forregulating current and voltage. This regulating functionality addressesvariations in the energy scavenged by the CT 610. For example, suchvariations can include moment-by-moment differences in the current flowthrough the conductor 660.

One means for regulating current and voltage includes a pre-regulatorcircuit 710. The pre-regulator circuit 710 includes an n channel fieldeffect transistor (“FET”) Q1, a voltage comparator U1, and associatedresistors R1-R13 and capacitors C2-C13. The pre-regulator circuit 710 isdesigned to take the output of the CT 610 and develop a voltage that ismatched to a power curve of the CT 610. This task is accomplished byconnecting the output of the CT 610 to a full wave bridge rectifiercircuit 705 to create a DC current from the AC current output from theCT 610. The full wave bridge rectifier circuit 705 includes four diodesD1-D4 and a capacitor C1. The capacitor C1 is tuned with the CT 610 toprovide voltage amplification for the DC output from the full wavebridge rectifier circuit 705.

The output of the full wave bridge rectifier circuit 705 is connected tothe FET Q1 and a diode D5 and charges holding capacitors C6 and C7.Typically, the holding capacitors C6 and C7 are several 100 micro-faradsin size. As the capacitors C6 and C7 charge, a comparator circuit 711including the voltage comparator U1 monitors the voltage. At apre-described voltage level, the FET Q1 is turned on to shunt excessenergy through the FET Q1. The diode D5 blocks the capacitors C6 and C7from discharging. Therefore, the only current through the FET Q1 is fromthe CT 610. Since this is a very low impedance path, very little heat isgenerated. As the voltage drops across the holding capacitors C6 and C7,the FET Q1 turns off, allowing the capacitors C6 and C7 to charge. Thisprocess continues as long as the power input from the CT 610 is morethan the power requirements of the load (radio or other active device)and charging of the battery BT1. Any unneeded power is dissipated toground.

In certain exemplary embodiments, the circuit 700 includes a currentsensor circuit 707, which calculates current in the conductor 660 basedon the fact that the current is directly proportional to the current onthe primary winding of the CT 610 divided by the number of secondarywindings of the CT 610. A burden resistor (combination of R1 and R2) isplaced on the negative tap 706 of the full wave bridge rectifier circuit705 to produce a voltage proportional to the value of the burdenresistor based on the amount of current flowing through the burdenresistor. The resistance of the burden resistor is typically small. Forexample, in certain exemplary embodiments, the resistance can beapproximately 0.25 ohms. The burden resistor creates a negative signalthat can be amplified to desired levels. The accuracy of the currentmeasurement depends on the CT's ability to remain linear whiledeveloping the circuit voltage required. This largely depends on thepermeability and area of the core and turns ratio of the CT 610.

The circuit 700 also includes a switching regulator circuit 715. Incertain exemplary embodiments, the switching regulator circuit 715includes a buck regulator topology including a buck regulator U3 andassociated resistors R14-R18 and capacitors C10 and C14-C15. Tests haveshown that, by regulating the voltage input to the switching regulatorcircuit 715 to be slightly above an exemplary CT's 610 optimal voltageof approximately 23 volts, a 6× current gain is achieved when regulatingdown to 3.3 volts. The 6× current gain reduces the need to supply largecurrents from the CT 610 at low line power which in turn reduces thestress on the FET Q1 when dissipating excess current at high line loads.As a theoretical example, consider a CT 610 with a 10 amp primarycurrent and 500 secondary turns, which would result in 10/500=0.02 ampsroot mean square (RMS). To get the DC current, one can multiply thecurrent by 0.707:0.02*0.707=0.014 amps DC. Multiplying this current bythe current gain of 6 yields 0.084 milliamps at 3.3 volts, orapproximately 0.25 watts of power. The actual current may deviate fromthe calculated current. For example, switch inefficiency can result in alower actual available DC current.

Feeding the output of the switching regulator circuit 715 to a batteryBT1 allows for an easy way to float charge the battery. This is achievedby isolating the battery BT1 from the output of the switching regulatorcircuit 715 by a small resistance R19. This allows the battery BT1 tocharge when the load is drawing less power than the CT 610 isharvesting. While the device being powered by the monitoring device 600is active (e.g., transmitting mode for a radio), the battery BT1 cansupply any excess current required by the device. As long as the totalpower into the battery BT1 from the CT 610 is greater than the totalpower out of the battery BT1 to the device, the battery BT1 will stay ina charged state. For example, the battery BT1 can have an optimumworking voltage of 3.3 volts and an acceptable working voltage range of3.2 to 3.4 volts.

In certain exemplary embodiments, the circuit 700 includes a batteryvoltage monitor circuit 720 that monitors the voltage of the batteryBT1. If the battery voltage monitor circuit 720 senses that the voltageof the battery BT1 is below a threshold value, the battery monitorcircuit 720 sends a signal, such as a “V LOW” signal, to a controllercircuit (not shown) that is operable to shut off power to the device. Incertain exemplary embodiments, the controller circuit can include amicrocontroller having configurable instructions for powering the devicedown immediately or via a controlled shutdown. Once a suitable voltageis sensed on the battery BT1, the controller circuit can provide asignal, such as a “POWER” signal, to the buck regulator U3 tore-energize the device.

To allow the circuit to start up, the voltage comparator U1 monitors thevoltage on the pre-regulator 710. When the voltage is below a definedvoltage limit, which may be based on the optimum voltage of the CT 610,the voltage comparator U1 holds the switching regulator circuit 715 inthe off state. When the voltage rises above a defined threshold value,which may be based on the optimum voltage of the CT 610, the voltagecomparator U1 enables the buck regulator U3, thereby allowing thecircuit 700 to supply a regulated voltage to the load and to charge thebattery BT1. If the voltage drops below a certain voltage, the voltagecomparator U1 can shut off the switching regulator circuit 715, therebyallowing the voltage to rise. As the voltage rises, the voltagecomparator U1 can turn the switching regulator circuit 715 back on. Thiscircuit 700, in combination with the configuration of the 610, allowsthe system to operate at minimum line power. In certain exemplaryembodiments, the circuitry 700 may provide for shut down powering of oneor more components. Shut down powering involves systematically poweringdown a device to prevent damage in the event of a loss of electricalpower.

Representative values for the components of the circuit 700 are listedbelow in Tables 1 and 2. A person of ordinary skill in the art havingthe benefit of the present disclosure will recognize that these valuesare merely exemplary, and other values may be chosen without departingfrom the spirit and scope of the invention.

TABLE 1 Exemplary Resistor Values for the Circuit 700 Circuit ComponentValue R1 0.05 Ω R2 0.05 Ω R3 1 kΩ R4 1 MΩ R5 2 MΩ R6 2 MΩ R7 105 kΩ R810 kΩ R9 2 MΩ R10 113 kΩ R11 10 kΩ R12 4.99 MΩ R13 1 kΩ R14 60.4 kΩ R1519.1 kΩ R16 604 kΩ R17 1 MΩ R18 100 kΩ R19 0.05 Ω R20 2 MΩ R21 787 kΩR22 1 MΩ

TABLE 2 Exemplary Capacitor Values for the Circuit 700 Circuit ComponentValue C1 1 μF C2 0.01 μF C3 33 pF C4 0.1 μF C5 0.1 μF C6 220 μF C7 220μF C8 0.1 μF C9 0.1 μF C10 0.1 μF C11 22 μF C12 0.1 μF C13 1 μF C14 22μF C15 680 pF C16 47 μF C17 0.1 μF C18 0.1 μF

FIG. 12 is a front view of two split core sections 805 and 815 of the CT610, in accordance with certain exemplary embodiments. FIG. 13 is a sideview of the split core section 805, in accordance with certain exemplaryembodiments. With reference to FIGS. 12-13, each split core section 805,815 is disposed within a corresponding one of the CT arms 612A and 612B.

In certain exemplary embodiments, the split core sections 805, 815 areformed by winding layers of metal around a magnetic form, such as amandrel, to form a core, and then splitting the core into two sections805 and 815. The core may be formed from any of a variety of differentmaterials, such as grain oriented silicon steel, supermalloy, permalloy,ferrites, and/or other materials. In certain exemplary embodiments, thecore is coated with an epoxy to ensure that a winding 905 disposed onone of the split core sections 805 or 815 does not short out to thesplit core section 805 or 815. The core may be coated either before orafter being split into the sections 805 and 815. In certain exemplaryembodiments, the core may be vacuum-impregnated with a varnish to holdlaminations of the core together and protect the core from moisture. Incertain exemplary embodiments, the thickness of the laminations isconfigured for 60 Hz operation.

In certain exemplary embodiments, some or all of each split core section805, 815 is covered in an insulating material. The insulating materialcan prevent direct contact between the conductive material in each splitcore section 805, 815 and the conductor 660. The insulating materialalso can protect the split core sections 805 and 815 from theenvironment. In addition, or in the alternative, the surfaces of thesplit core sections 805 and 815 may be covered with a thin coating toprotect them from possible corrosive elements in the environment. Forexample, the coating can between 0.2 mil and 0.6 mil thick.

In certain exemplary embodiments, end surfaces 805A and 805B and 815Aand 815B of the split core half sections 805 and 815, respectively, aresubstantially flat and coplanar. In certain exemplary embodiments, thesplit core sections 805 and 815 and any coating and/or insulationthereon are sized and configured such that there is only a shortdistance 825 between adjacent pairs of the end surfaces 805A-805B and815A-815B. In certain exemplary embodiments, a lap taping describedbelow with reference to FIG. 16 starts and ends at location 845 on asurface of the split core section 805.

FIGS. 14-15 depict the split core sections 805 and 815, in accordancewith certain exemplary embodiments. Referring to FIGS. 14-16, the splitcore section 805 includes a winding 905 of an electrical wire 930 (FIG.16) that is disposed around a member 807 of the split core section 805.In certain exemplary embodiments, the winding 905 is locatedapproximately in the center of the split core section 805, extendingapproximately 28 degrees toward each end surface 805A and 805B of thesplit core section 805. The winding 905 is electrically coupled to theconductors 670A and 670B of the electrical connector 670 as described inmore detail with reference to FIG. 16.

FIG. 16 depicts a method 1600 for forming the winding 905 on the member807 of the CT split core section 805, in accordance with certainexemplary embodiments. In step 1645, a tape 920, such as a fiberglasstape, is wrapped around a middle segment 805C of the CT split coresection 805. In the exemplary embodiment depicted in FIG. 16, the tape920 starts and ends at approximately 35 degrees from the end surfaces805A and 805B of the split core section 805. The tape 920 completelyoverlaps the outer diameter of the split core section 805 and partiallyoverlaps each side of the inner diameter of the split core section 805.

In step 1650, another tape 921, such as a Kapton® brand tape, is appliedto a middle portion of the middle segment 805C with one-half lap taping.In the exemplary embodiment depicted in FIG. 16, the tape 921 starts andends at approximately 50 degrees from the end surfaces 805A and 805B ofthe split core section 805. In certain exemplary embodiments, threelayers of the tape 921 are applied to the split core section 805 withone-half lap taping, reversing the direction of the tape 921 for eachlayer.

In step 1655, a wire 930 is placed on the split core section 805. Instep 1660, the wire 930 is wrapped around the split core section 805multiple times to form the winding 905. For example, the wire 930 may bewrapped around the split core section 805 five hundred times to form thewinding 905.

In step 1665, a tape 922 is placed over a first end 930A of the wire 930to hold the first end 930A in place. In step 1670, another tape 923 isapplied over the winding 905, from the tape 922 to an end of the splitcore section 805, and a second end 930B of the wire 930 is bent back tobe substantially parallel and adjacent to the first end of the wire930A. In step 1675, another tape 924 is placed over the first and secondends 930A and 930B and the tape 922.

In step 1680, another tape 925 is wrapped around the winding layers 905,leaving the first and second ends 930A and 930B exposed. In step 1685,the first and second ends 930A and 930B are connected to the electricallead wires 670A and 670B respectively, thereby electrically coupling theelectrical lead wires 670A and 670B to the winding 905. In certainexemplary embodiments, the first end 930A is twisted and soldered withthe lead wire 670A and the second end 930B is twisted and soldered withthe lead wire 670B.

In step 1690, the electrical lead wires 670A and 670B are bent in thedirection of the electrical connector 670 and pressed against the tape925. In step 1695, the electrical lead wires 670A and 670B are securedin place with a tape 926. In certain exemplary embodiments, a dielectrictape suitable for high temperature applications is used for each oftapes 922-926. In certain exemplary embodiments, the split core section805, including the winding 905, is then covered with an insulatingmaterial and overmolded in plastic.

FIG. 17 is a top elevation view of the CT arm 612A of the split coresection 805, in accordance with certain exemplary embodiments. FIG. 18is a side cross sectional view of the CT arm 612A, in accordance withcertain exemplary embodiments. FIG. 19 is a top elevation view of the CTaim 612B of the split core section 815, in accordance with certainexemplary embodiments. FIG. 20 is a side cross sectional view of the CTarm 612B, in accordance with certain exemplary embodiments.

With reference to FIGS. 7 and 17-20, the proximal end 612AB of the CTarm 612A includes two apertures 1005 and 1015. Similarly, the proximalend 612BB of the CT arm 612B includes two apertures 1055 and 1065. Whenthe CT arms 612A and 612B are coupled to the housing 620, the apertures1005 and 1055 substantially overlap with one another and are alignedwith a connector 682. The apertures 1005 and 1055 are sized and shapedto receive the connector 682, which extends through the apertures 1005and 1055, thereby coupling the CT arms 612A and 612B to the housing 620.When the CT arms 612A and 612B open and close, the CT arms 612A and 612Bpivot around at least a portion of the connector 682, which defines anaxis of movement for the CT arms 612A and 612B.

Each of the second apertures 1015 and 1065 is sized and configured toreceive a corresponding connector 680A and 680B. When the CT arms 612Aand 612B are coupled to the housing 620, each connector 680A and 680Bextends through its respective aperture 1015, 1065. The connectors 680Aand 680B prevent the CT alms 612A and 612B from moving more than apredetermined distance apart from one another.

Each CT arm 612A, 612B includes a spring connection 1025, 1075,respectively, which protrudes from a main body portion 612AC, 612BC,respectively, of the CT arm 612A, 612B. These spring connections 1025and 1075 are sized and configured to attach the CT spring 611A to the CTarms 612A and 612B. For example, as illustrated in FIG. 8, a first end611AA of the CT spring 611A can be coupled to the spring connection1025, and a second end 611AB of the CT spring 611A can be coupled to thespring connection 1075. Although not readily visible in the figures,similar spring connections are disposed on the CT arms 612A and 612B,opposite the spring connections 1025 and 1075, for attaching the CTspring 611B to the CT arms 612A and 612B.

As set forth above, the CT arms 612A and 612B remain in a closedposition unless acted on by an outside force. The springs 611A and 611Benable this functionality. The springs 611A and 611B are biased to applyforces to the CT arms 612A and 612B, in the direction of the closedposition. As set forth above, when the conductor 660 enters the CT 610,the conductor 660 overcomes those forces, thereby causing the CT arms612A and 612B to open.

As shown in FIGS. 18 and 20, in certain exemplary embodiments, the splitcore sections 805 and 815 and CT arms 612A and 612B have different crosssectional areas. In part, this difference in cross-sectional area may bebased on the fact that only the split core section 805—and not the splitcore section 815—includes winding 905. Thus, the CT 610 includes onlyone winding 905. In certain alternative exemplary embodiments, both thesplit core section 805 and 815 include a winding 905.

FIGS. 21-24 illustrate the housing 620 of the monitoring device 600, inaccordance with certain exemplary embodiments. With reference to FIGS.21-24, as set forth above, the housing 620 includes a member thatdefines an internal cavity in which various components of the monitoringdevice 600 are disposed. For example, the housing 620 may enclose thecircuitry of the CT 610. In addition, the housing may enclose one ormore devices that are powered by the circuitry of the CT 610. A personof ordinary skill in the art having the benefit of the presentdisclosure will recognize that the housing 620 can vary in size andshape. For example, the size and shape of the housing 620 can depend onthe sizes and shapes of the components to be accommodated therein. Thehousing 620 can also be constructed from any suitable material that canwithstand exposure to environmental conditions. The housing 620 can alsobe enclosed via a molding process.

As best seen in FIG. 24, in certain exemplary embodiments, the housing620 includes a space 621 in which an additional device, such as anenergy storage device (not shown), may be installed. The energy storagedevice can power one or more devices enclosed in the housing 620 andnormally powered by the circuitry of the CT 610 when the conductor 660is de-energized or when the conductor 660 is not providing a sufficientamount of energy. For example, the energy storage device can include abattery, a rechargeable battery (such as the battery BT1 depicted inFIG. 11), a supercapacitor, or another energy storage device.

When the monitoring device 600 includes an antenna 650, the housing 620can include an aperture 1110 through which at least a portion of theantenna 650 can extend. As discussed above, the antenna 650 may bepresent when the device powered by the monitoring device 600 is acommunications device, such as a radio or a repeater. In addition to, orin place of the antenna 650, the aperture 1110 may receive one or moreother components. For example an indicator that provides an indicationof the status of the monitoring device 600 or a status of a devicepowered by the monitoring device 600 can be at least partially disposedwithin the aperture 1110. Although depicted in the figures as beingsubstantially round with one flat side, a person of ordinary skill inthe art having the benefit of the present disclosure will recognize thatthe aperture 1110 can have any of a number of different sizes and shapesdepending on the application of the monitoring device 600.

As discussed above, the CT 610 is coupled to the housing 620. FIGS. 25and 26 show mechanisms used to couple the CT 610 to the housing 620, inaccordance with certain exemplary embodiments. In particular, FIG. 25shows an exemplary female connector 680 that corresponds to each of theconnectors 680A and 680B in FIG. 7. As set forth above, the connectors680A and 680B may be used to couple the CT 610 to the housing 620 viathe apertures 1015 and 1065 in the CT arms 612A and 612B, respectively.For example, the connector 680A can be used to couple the CT 610 to thehousing 620 via the aperture 1015 in the CT arm 612A. Similarly, theconnector 680B can be used to couple the CT 610 to the housing 620 viathe aperture 1065 in the CT arm 612B. FIG. 26 shows the exemplary maleconnector 682 described above with reference to FIGS. 7 and 17-20.

FIGS. 27-31 illustrate the clamp arm 632B, in accordance with certainexemplary embodiments. With reference to FIGS. 8 and 27-31, the clamparm 632B includes a clamp pad 633B that has clamp slots 910. When themonitoring device 600 is installed on a conductor 660 and the clamp arms632A and 632B are closed around the conductor 660, the clamps pads 633Aand 633B secure the monitoring device 600 to the conductor 660. Theclamp slots 910 help to minimize the motion of the conductor 660relative to the clamp arms 632A and 632B.

In certain exemplary embodiments, the clamp arm 632B includes apertures915A and 915B for coupling one or more additional clamp pads 1505 (SeeFIGS. 31 and 32) to the clamp arm 632B, over the clamp pad 633B. Thisfeature allows the monitoring device 600 to couple to conductors 660 ofvarious sizes. For larger conductors 660, additional clamp pads 1505 maynot be required. For smaller conductors 660, clamp pads 1505 of variousdifferent sizes may be installed onto the clamp arm 632B via theapertures 915A and 915B.

FIG. 31 is a front elevation view of a clamp pad 1505 coupled to theclamp arm 632B, in accordance with certain exemplary embodiments. FIG.32 is a cross sectional view of the clamp pad 1505, in accordance withcertain exemplary embodiments. With reference to FIGS. 8 and 31-32, theclamp pad 1505 includes tabs 1510A and 1510B that correspond to theapertures 915A and 915B on the clamp arm 632B. To allow the monitoringdevice 600 to be used with different sized conductors 660, the tabs1510A and 1510B may be placed in various different positions thatcorrespond to the appropriate dimensions of the conductor 660. Inaddition, or in the alternative, the clamp pad 1505 may be placed invarious different positions that correspond to the appropriatedimensions of the conductor 660.

FIG. 33 is a side elevation view of a clamp spring 631, such as clampspring 631A or 631B of FIG. 8, in accordance with certain exemplaryembodiments. The clamp spring 631 supplies at least a portion of theforce required to move one of the clamp arms 632A and 632B into a closedposition when the monitoring device 600 is installed. Each of the distalends 1605 and 1610 of the clamp spring 631 includes a curved portion1605A and 1610A, respectively. This curve provides reduced likelihood ofelectric interference from the clamp spring 631, as compared to clampsprings that have sharp ends. Although illustrated in FIG. 33 asincluding nearly 680 degree curves, a person of ordinary skill in theart having the benefit of the present disclosure will recognize that anydegree curve may be used in each of the curved portions 1605A and 1610A.

FIGS. 34-37 illustrate a power line monitoring device 3400, inaccordance with certain alternative exemplary embodiments. Withreference to FIGS. 6-10 and 34-37, the monitoring device 3400 issubstantially similar to the monitoring device 600 described aboveexcept that the antenna 3410 of the device 3400 extends from a side face620A of the housing 620 and is electrically coupled to the conductor 660(FIG. 8) via springs 611A and 3415.

As set forth above, when the monitoring device 3400 is installed on theconductor 660, the conductor 660 engages the spring 611A. The second end611AB of the spring 611A is electrically coupled to a first end 3415A ofthe spring 3415. In certain exemplary embodiments, the ends 611AB and3415A of the springs 611A and 3415, respectively, electrically engageone another by each being coupled to the spring connection 1075 (FIG.19), substantially as described above (in connection with the end 611AB)with reference to FIG. 19.

A second end 3415B of the spring 3415 is electrically coupled to theantenna 3410 and/or one or more interior components of the monitoringdevice 3400. For example, in certain exemplary embodiments, the spring3415 is electrically coupled to the circuit board 3405 of the monitoringdevice 3400. A fastener 3420, such as a mounting stud or bolt, extendsthrough the side face 620A of the housing 620. For example, the fastener3420 can be an antenna connector 655 that connects the antenna 3410 tothe housing 620, substantially as described above with reference to FIG.6. In certain alternative exemplary embodiments, the antenna 3410 can bedisposed within the housing 610. In such embodiments, the fastener 3420still may extend through the side face 620A to facilitate electricalcoupling of the spring 3415 and the interior component(s) of themonitoring device 3400, substantially as described herein. The secondend 3415B of the spring 3415 is coupled to a first end 3420A of thefastener 3420 that is disposed substantially outside the housing 620. Aconductive connector 3425, such as a wire, is coupled to a second end3420B of the fastener 3420 that is disposed substantially within thehousing 620. The connector 3425 is coupled to the circuit board 3405and/or one or more other components disposed within the housing 620. Forexample, the connector 3425 can be coupled to a ground reference point3405A on the circuit board 3405. Generally, the monitoring device 3400is mounted to the conductor 660 such that the monitoring device 3400 is“floating” without an Earth ground. The term “ground reference point” isused herein to refer to a circuitry reference point from which othervoltages are measured, regardless of whether the reference pointcorresponds to Earth ground.

Thus, the antenna 3410, circuitry, and/or internal components of themonitoring device 3400 are electrically coupled to the conductor 660.This electrical coupling allows the device 3400 and the circuitry andantenna 3410 thereof to have substantially the same voltage potential asthe potential of the conductor 660. Accordingly, there is asubstantially equalized or uniform electric field around the monitoringdevice 3400. The substantially equal voltage potential and electricfield allow communications with the monitoring device 600 to havereduced noise and interference, as compared to communicating power linemonitoring devices that have different voltage potentials than theconductors 660 to which they are mounted. A person of ordinary skill inthe art having the benefit of the present disclosure will recognize thatmany other means besides the springs 611A and 3415 and connector 3425may be used to bring the antenna 3410, circuitry, and/or other internalcomponents of the monitoring device 3400 to the line potential of theconductor 660 without departing from the spirit and scope of theinvention. For example, one or more electrically conductive wires, pins,or other members could be used in place of the spring 3415 toelectrically couple the spring 611A and the connector 3425 together.

When a user mounts the monitoring device 3400 to the conductor 660, thevoltage potential of the monitoring device 3400 increases from a basevoltage value to the voltage potential of the conductor 660. Generally,the increase is significant, on the order of a few hundred volts. Anabrupt increase of significant voltage potential can cause the springs611A and 3415 to develop electrical arcing or corona discharge, whichcan be harmful to the monitoring device 3400 and cause undesirableinterference in communications with the monitoring device 3400.

In certain exemplary embodiments, as depicted in FIG. 37, the monitoringdevice 3400 includes a pad 3430, which is disposed between the conductor660 and the spring 611A and slows down the rate of voltage potentialchange when the monitoring device 3400 is mounted to the conductor 660.The pad 3430 includes a substantially elongated sheet of semi-conductivematerial that is electrically resistive. For example, the pad 3430 canhave an electrical resistance of between about 7 and about 40 ohms/cm.Slowing down the rate of voltage potential change decreases oreliminates the likelihood of electrical arcing or corona discharge whenmounting the device 3400 to the conductor 660. In certain exemplaryembodiments, the pad 3430 includes apertures 3430A and 3430B throughwhich the CT arms 612A and 612B, respectively, extend. Sizes and shapesof the apertures 3430 and/or flexibility of the material of the pad 3430allows the CT arms 612A and 612B to open and close without adverselyimpacting the pad 3430.

Although specific embodiments have been described above in detail, thedescription is merely for purposes of illustration. It should beappreciated, therefore, that many aspects of the invention weredescribed above by way of example only and are not intended as requiredor essential elements of the invention unless explicitly statedotherwise. Various modifications of, and equivalent steps correspondingto, the disclosed aspects of the exemplary embodiments, in addition tothose described above, can be made by a person of ordinary skill in theart, having the benefit of this disclosure, without departing from thespirit and scope of the invention defined in the following claims, thescope of which is to be accorded the broadest interpretation so as toencompass such modifications and equivalent structures.

1. An overhead device, comprising: a device configured to be mounteddirectly to a power line, the device comprising electrical circuitrythat includes a ground reference point; and means for electricallycoupling the ground reference point of the device to the power line suchthat the ground reference point and the power line have substantiallyequal voltage potentials.
 2. The overhead device of claim 1, furthercomprising a sensor that collects information regarding the power line.3. The overhead device of claim 2, wherein the device comprises acommunications device configured to communicate with another device thatis located remote from the overhead device, the communications devicebeing configured to communicate at least a portion of the informationcollected by the sensor to the other device.
 4. The overhead device ofclaim 2, wherein the collected information comprises informationregarding at least one of a current of the power line, a voltage of thepower line, a temperature on the power line, and whether a vibration ispresent on the power line.
 5. The overhead device of claim 1, furthercomprising: a current transformer comprising a member about which awinding is at least partially disposed, the current transformerreceiving an induced current on the winding via magnetic flux energygenerated by alternating current on the power line; and a circuitelectrically coupled to the winding and converting the inducted currentreceived by the current transformer into an electrical energy thatpowers the device.
 6. The overhead device of claim 5, wherein theelectrical circuitry of the device comprises the circuit electricallycoupled to the winding.
 7. The overhead device of claim 5, wherein thecurrent transformer further comprises two arms that are positionable inopen and closed positions, one of the arms comprising the member andwinding, and wherein the power line extends at least partially throughan opening defined by the arms when the arms are in the closed position.8. The overhead device of claim 7, wherein the current transformerfurther comprises a spring that biases the arms towards the closedposition, and wherein the means for electrically coupling comprises thespring.
 9. The overhead device of claim 1, further comprising means forslowing a rate of voltage potential change of the ground reference pointof the device when the overhead device is mounted to the power line. 10.The overhead device of claim 9, wherein the means for slowing comprisesa semi-conductive material that is disposed substantially between thepower line and the means for electrically coupling.
 11. The overheaddevice of claim 1, wherein the device has a voltage potential that issubstantially equal to the voltage potential of the power line.
 12. Apower line monitoring device, comprising: a sensor that collectsinformation regarding a power line to which the overhead device ismounted; a communications device that communicates at least a portion ofthe information collected by the sensor to a location remote from theoverhead device; and a circuit board that comprises circuitry associatedwith the sensor and the communications device, the circuitry comprisinga ground reference point that is electrically coupled to the power linewhen the overhead device is mounted to the power line, a voltagepotential of the ground reference point being raised based on a voltagepotential of the power line when the overhead device is mounted to thepower line.
 13. The power line monitoring device of claim 12, furthercomprising means for slowing a rate of voltage potential change of theground reference point when the overhead device is mounted to the powerline.
 14. The power line monitoring device of claim 13, wherein themeans for slowing comprises a semi-conductive material disposedsubstantially between the power line and the spring.
 15. The power linemonitoring device of claim 13, wherein the means for slowing comprises asemi-conductive material that has a resistivity of at least about 5 ohmsper centimeter.
 16. The power line monitoring device of claim 12,wherein the voltage potential of the ground reference point is raised tobe substantially equal to the voltage potential of the power line. 17.The power line monitoring device of claim 12, wherein the collectedinformation comprises information regarding at least one of a current ofthe power line, a voltage of the power line, a temperature on the powerline, and whether a vibration is present on the power line.
 18. Thepower line monitoring device of claim 12, further comprising: a currenttransformer comprising a member about which a winding is at leastpartially disposed, the current transformer receiving an induced currenton the winding via magnetic flux energy generated by alternating currenton the power line; and a circuit electrically coupled to the winding andconverting the inducted current received by the current transformer intoan electrical energy that powers the communications device.
 19. Thepower line monitoring device of claim 17, wherein the currenttransformer further comprises two arms that are positionable in open andclosed positions, one of the arms comprising the member and winding, andwherein the power line extends at least partially through an openingdefined by the arms when the arms are in the closed position.
 20. Thepower line monitoring device of claim 18, wherein the currenttransformer further comprises a spring that biases the arms towards theclosed position, and wherein the spring electrically couples the powerline to at least one electrically conductive member that is electricallycoupled to the ground reference point when the overhead device ismounted to the power line.
 21. A power line monitoring device,comprising: a sensor that collects information regarding a power line towhich the overhead device is mounted; a communications device thatcommunicates at least a portion of the information collected by thesensor to a location remote from the overhead device; a circuit boardthat comprises circuitry associated with the sensor and thecommunications device, the circuitry comprising a ground referencepoint; a housing that at least partially encloses the circuit board; afirst electrically conductive member coupled to the housing, the firstelectrically conductive member being disposed outside of the housing andelectrically contacting the power line when the overhead device ismounted to the power line; and at least a second electrically conductivemember extending through the housing and electrically coupling the firstelectrically conductive member to the ground reference point of thecircuitry, thereby raising a voltage potential of the ground referencepoint in accordance with a voltage potential on the power line when theoverhead device is mounted to the power line.
 22. The power linemonitoring device of claim 21, wherein the voltage potential of theground reference point is raised to be substantially equal to thevoltage potential of the power line.
 23. The power line monitoringdevice of claim 21, further comprising means for slowing a rate ofvoltage potential change of the ground reference point when the overheaddevice is mounted to the power line.
 24. The power line monitoringdevice of claim 23, wherein the means for slowing comprises asemi-conductive material that is disposed substantially between thepower line and the first electrically conductive member.
 25. A methodfor monitoring a power line, comprising the steps of: mounting a powerline monitoring device to a power line, the power line monitoring devicecomprising a sensor, communications device, and circuitry, wherein thecircuitry comprises a ground reference point; collecting, by the sensor,information regarding the power line; communicating, by thecommunications device, at least a portion of the information collectedby the sensor to a location remote from the power line monitoringdevice; and electrically coupling the ground reference point of thecircuitry to the power line so that a voltage potential of the groundreference point is raised based on a voltage potential of the powerline.
 26. The method of claim 25, further comprising the step ofharvesting energy from the power line to power the communicationsdevice.